The 2N6051 is a silicon complementary Darlington transistors in a TO3 type case designed for general–purpose amplifier and low–frequency switching applications.
High DC Current Gain: hFE = 3500 Typ @ IC = 5A
Collector–Emitter Sustaining Voltage: VCEO(sus) = 100V Min @ 100mA
Monolithic Construction with Built–In Base–Emitter Shunt Resistors
TO-3 package. Manufactured by Harris.